. R7 _' i) ^* h- i' e k/ ?0 _代入以下代码,得:11,9,4,2,1,6 滑稽~# s1 f a) V& o" r8 E5 P7 k- r
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#include <iostream>7 h3 I4 ^( e" t! j$ v+ l
#include <string.h>0 f* g! Q& W* p% `* q8 i4 y
using namespace std;
z6 P% w$ J5 G6 [, A( I$ s6 ?' ~% Htemplate <class T>
" _6 o0 y5 B# Tclass Node
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public:
1 L* ~! C1 N/ j1 Q" k% x. N T data;. r- ?, Z, {) k: r# d/ O
Node<T> *next;
B2 K. D3 F }" ]7 {& v+ u { Node()
7 j ~/ m( T! Z* R1 G {& H4 S" a4 n; U( K, i
this->next = NULL;, i0 K$ D% `- r) p
}
7 `+ K1 m& j: w. j6 d1 e Node(T data,Node<T> *next=NULL)& g* w1 M, \! u+ M
{
! y, b- d& ~+ u, _ this->data = data;& ], c! N# V" [# i$ U0 c
this->next = next;/ X, A4 r7 H; L: |; y" s7 g
}
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template <class T>
% y0 d/ I- N0 f4 y/ lclass LinkedStack9 E6 M" ]2 x$ ^: B
{
/ W5 ?- ?" r+ \2 ~9 c1 o- hprivate:+ K- O2 u A) A% o9 N: T
Node<T> *top;
- \! q" g1 q+ c( Mpublic:
4 Z' R- O, k4 j; W LinkedStack();
, F! K& o) J/ j5 Z7 ` ~LinkedStack();
3 T+ r- b# o# o# \0 D bool isEmpty();1 N* T' U# R9 t0 h2 `
void push(T x);
) D' r4 D/ ^3 x I0 D% f% l- S T pop();& B4 M! F# O7 M' y* v4 S- B
T get();
, u# Z }" o: J) h8 M" I; ~1 G" @};
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template <class T>: `# O; j* g9 }6 Y5 w. N- U
LinkedStack<T>::LinkedStack()6 L5 p! d+ B/ W' t+ S; @1 P J, n) z
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top = NULL;
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8 M. N: ~7 \+ u. J; _template <class T>
|% s9 Z+ X) p, JLinkedStack<T>::~LinkedStack()% I5 b( n$ R1 M! w6 ^
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Node<T> *p = top;! t+ n5 W# [ S5 }" {9 h9 b7 t
Node<T> *q;' J; m; k4 ]4 V6 c
while(p!=top)
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q = p;
* U4 Y0 l# X- D! f7 m& _* O8 M5 e p = p->next;
* i$ @- F5 l7 ^ delete p;
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top = NULL;7 A3 B# _7 C; |
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template <class T>- _; d4 ^. O2 {: M
bool LinkedStack<T>::isEmpty()
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return top == NULL;
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: ?6 s- x2 j1 K% a* Etemplate <class T>% L7 e" |/ t4 K4 U$ B3 Y. b
void LinkedStack<T>::push(T x)
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1 n$ A! U: G* X' r/ m top = new Node<T>(x,top);
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/ _# R C; Q9 ~2 L5 ptemplate <class T>
& w, ~ X% B/ X4 I( p& MT LinkedStack<T>::pop()
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if(!isEmpty())
( r- y3 f9 {$ n8 m/ D {
9 v9 j4 w' u$ A4 v T x = top->data;
! q, Y2 E* L# q5 z; D- R; y' d2 g Node<T> *p = top;6 I3 Z. D0 K! C/ i
top = top->next;$ E9 a. W* o! R# G9 x
delete p;, H# E/ N3 w" C# p4 X2 U8 R- o
return x;$ Z* ]0 C! P+ M; r; h
}
+ N# [5 F( _6 ] throw "空栈,不能执行出栈操作";# _8 k# Q7 m% k$ K) V% ^+ A9 c
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template <class T> C. p: x1 ~7 p# {
T LinkedStack<T>::get()
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if(!isEmpty())
' \) F3 a& T; t* C8 j7 g2 N {
1 l" R* R& Q% j% y4 n; W return top->data;/ N4 E5 r, k- f
}
- F# y& x, j* M O* D* {) Y: V throw "空栈,不能获得栈顶元素";) l$ ]* v C' _ `" e3 u$ v
}
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4 b- r6 p1 H2 y3 k+ A# Jchar * toPostfix(char *expstr)# R a) e e6 n7 G
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LinkedStack<char> stack;
4 f0 }5 q) V V* ^! ^' w char *postfix = new char[strlen(expstr)*2];; P( ~3 ^9 [+ z3 c
int i=0;0 A a, B6 }. J" A6 D8 V8 c
int j=0;
- A; C& W- V% e' K' z( L9 r7 P6 w char out ;4 A4 d7 ]4 E* M3 Z# ^0 I8 W% G$ X
while(expstr!='\0')
Y, L6 T% _) X9 A6 e" r2 \ {
" }) C* N% I- q l5 Y switch(expstr)5 {' X2 e+ S0 b0 v+ j! g1 r
{
! d3 D& c/ n) p- t3 U. t3 k case'+':
. ?4 `+ X4 O3 ^% Y0 g8 J2 `* K case'-':
% ?/ X. m" O4 L# \+ R7 e: E while(!stack.isEmpty()&&stack.get()!='(')
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postfix[j++] = stack.pop();
) f1 k0 Q. u& q& p& a }
+ J4 m, c. B6 a; t) s! D stack.push(expstr[i++]);3 | H2 z3 ~1 I3 J ]! e# T
break;
/ O5 t8 S/ E. X+ M7 ?: k& V3 T2 D7 u case'*':
$ k* K1 o) Z4 d4 Q case'/':# [0 \! x: F+ E- \" _
while(!stack.isEmpty()&&(stack.get()=='*'||stack.get()=='/'))
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postfix[j++] = stack.pop();
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stack.push(expstr[i++]);
+ S, Q. G9 b8 C! [* @ C break;: `) D% V5 n" S! c3 o- q9 P- A
case'(':stack.push(expstr[i++]);
' |8 z& ^) P$ r4 [4 U- K3 U break;
- a2 G4 v) O( U- T! G% Q) t. v case')':out = stack.pop();8 u4 S0 }+ |* l' m+ l' j' }
while(!stack.isEmpty()&&out!='(')9 j8 t- C8 Z- y) E+ @5 B) e
{( |. k# v. O4 B" }0 r
postfix[j++] = out;- Q0 N; U- ?, ?* {
out = stack.pop();' O2 c: a4 @- `! l
}; Q2 M) t3 H; b
i++;" P& P$ ?/ w$ j/ `9 s' s
break;& Q. }% r2 M p1 i, A7 [% e
default:( Y6 d9 L Z2 z# C
while(expstr>='0'&&expstr<='9'&&expstr!='\0')
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postfix[j++] = expstr[i++];
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w' o z' t8 V- y, \( ?, v7 S postfix[j++]=' ';5 I) b4 s' c! N* ?; K
break;! i; I9 T' o0 J% a8 x$ q
}5 Y8 P1 x* ?; L! r+ M2 Y, }
}
+ t |5 x7 b8 z4 `) S; q5 C/ ~ while(!stack.isEmpty())
6 B5 A, e7 x, _0 c {
( n& m+ b; R6 R" u' J9 ^* T6 { l postfix[j++]=stack.pop(); j5 t; z. g- k/ r! U
}
/ r% h1 Z% h! d: x/ | R postfix[j]='\0';
& d+ S+ ]- C! @% t( Q6 B return postfix;: @- i: l0 V: o. w7 n4 P: y
}. |) v1 t& o1 I1 T
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int value(char *postfix)
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" V4 e$ o9 g$ V" c _) `5 r LinkedStack<int> stack;3 E/ B2 |1 ^% Q8 W) w
int i=0;1 a) p& A. k5 `% W- X
int result = 0;
6 I, M. k) V1 H- |- E- W' _ while(postfix!='\0')
" d; X& v1 n! o4 o {
6 k8 Z1 b% \, }% L l if(postfix>='0'&&postfix<='9')
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result = 0;. d% n7 o. {) W
while(postfix!=' ')
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result = result*10+postfix[i++]-'0';
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i++;
; A" h4 w5 n! j2 n ]( @9 H9 e stack.push(result);
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else' g' n& R% u. S6 `, S N
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if(postfix!=' ')
* r7 y6 N+ b8 b( x {
3 ^& U9 i. u- b3 z int y = stack.pop();
* {) Z% Z) H A$ d/ f* M int x = stack.pop();
$ p& G& G2 ]/ d( K: h switch(postfix)+ u9 R. p$ T% G' l# i! L( o
{# r. b6 _( [9 H; b9 v
case'+':result = x + y;/ J! T' N. H& F( o7 A$ M# P
break;3 ^$ h# u2 W/ l6 l9 U
case'-':result = x - y;) X6 x j+ u* Z& V7 Q
break;
+ ^- B( ?8 t/ B case'*':result = x *y;4 O" Q4 P2 ?5 f% q% B
break;
! J7 D& A1 s* r case'/':result = x / y;9 ?; M4 J% s) I- Y9 E R6 G
break;. I, J/ ^+ V+ t
}
6 @) \! Z( m4 M( J$ g) k stack.push(result);
8 b" _7 X! t q: q }
+ i* Q1 L9 a5 s+ e4 f0 z i++;
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}
N# A' m2 t: s5 ~ return stack.pop();
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" t" V8 @$ D: K* H) x9 a! S# [int main()7 c/ i' K' B1 }+ n _7 a1 n7 }. b6 h
{
( @* ] i9 c6 a9 q/ J7 S5 x3 { //char *expstr = "121+10*(52-49+20)/((35-25)*2+10)";
7 X: k1 d& r8 b8 p cout << "请输入表达式:";4 E- \8 ]7 Q9 D# _+ U8 r
//char *a ;
8 x/ b F! p' G8 U1 h s //cin >> *a;: o( ]( |, q( ]1 C' v+ C! x
char expstr[20]={0};6 H. ^9 ]' b1 Y# F
while(1)
9 M h$ z8 n; K L- Y6 t9 t! }' V {
! w8 d* y. B% g6 A) i0 q cin>>expstr;* Q, n, g; |, S2 f: O5 R! [
char *postfix = toPostfix(expstr);9 E# W' g9 U3 {# F9 d) C6 ~
cout << "expstr= "<<expstr << endl;% N) b* c2 U0 n! A
cout << "postfix= "<<postfix<<endl;; U- L3 U4 |, v' V/ H6 z. v1 J1 P( C7 k
cout << "value= "<<value(postfix) << endl;
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* Q. M- S6 Z( _8 e return 0;
7 M6 S4 J( V3 p9 w z4 D' o} |